6 March, 2013
A powerful coastal storm will impact Massachusetts beginning late tonight and lasting through Friday morning. The NWS has issued a Coastal Flood Warning for north and east facing shorelines based on a high confidence for high winds, storm surge, and moderate to major coastal flooding in these areas. The Coastal Flood Warning is in effect through 10:00 a.m. Friday.
In addition, the National Weather Service (NWS) has continued a Winter Storm Watch for Central and Eastern Massachusetts for late Wednesday night through Friday morning. While uncertainty remains on precipitation amounts, the risk for 6-12 inches of heavy wet snow continues across Eastern Massachusetts.
Forecast information is as follows:
Timing
Scattered light snow and rain showers are expected to develop today and continue into this evening with little accumulation. Heavy snows and high coastal winds will begin overnight and continue into Friday morning.
Precipitation
Uncertainty remains on precipitation amounts and temperatures, however the risk of heavy wet snow (6 to 12”) across central and eastern Massachusetts remains, with a sharp cutoff in snowfall amounts likely across inland portions of the Commonwealth. While the rain/snow line remains uncertain, indications are that it may set up across Southeast Massachusetts or Upper Cape Cod.
Winds
Wind gusts of 40-55 mph along the coast are expected along the coast, with the strongest winds expected across the Southeast coastal plain during the day on Thursday. Significant long duration winds may occur along the Southeast coast for a 36 hour period (late Wednesday night into Friday) with the strongest impacts across Plymouth County, Cape Cod, and the Islands. Inland, winds may gust up to 25-20 mph.
Power Outages
Given the combined impacts of high wind and heavy snow accumulation, scattered power outages remain a concern across Eastern Massachusetts.
Coastal Impacts and Flooding
The areas hardest hit by the February Blizzard (Essex, Plymouth and Barnstable county coastlines), the Islands, and exposed coastal areas are expected to be most affected by coastal flooding.
Moderate coastal flooding, with pockets of major flooding, are anticipated during the Thursday morning (6:30 to 8:00 a.m.) high tide cycle, with a storm surge of 2 ½ - 3 feet and waves up to 30 feet offshore. Moderate to major flooding is expected for the Friday morning (7:30 to 9:00 a.m.) high tide cycle. For the Thursday evening high tide cycle (7:00 to 8:30 p.m.) minor impacts are possible but with lesser concern then the two morning tides.
NWS expects the Thursday morning high tide to approach the same degree of severity as the flooding during the February 8-9 Blizzard. The Friday morning high tide could potentially be more severe than the flooding experienced during the Blizzard.
NWS anticipates significant to severe beach erosion on north- and east-facing shores Thursday morning through Friday morning with some erosion lingering into Saturday morning.
Coastal communities can view inundation maps at the following NWS link: http://www.erh.noaa.gov/box/inundation/coastalInundation.html.
Marine Impacts
This is a severe storm for the marine community, with potential life-threatening impacts. The seas will be 25-30 feet and there will be extended periods of high winds with gusts up to 55 knots likely.
MEMA remains at a Level IV (Steady State) and continues to monitor the situation. Updates will be provided as needed.
